In odontotherapy, it has generally been carried out to remove completely morbid parts of a teeth and, then, fill a suitable restoration material therein for the adjustment of the form of a tooth. However, when the morbid parts of a tooth spread to the proximal surface of the tooth, it is required that, after restoration, the proximal contact relation (esp., the interproximal distance) of the portion of the tooth restored and the proximal surface adjacent thereto be restored to a proper state.
In the tooth that is not restored and not morbid, it is also important that the proximal contact relation (esp., the interproximal distance) of the adjacent two teeth be confirmed before restoration.
More specifically, when the proximal contact relation (esp., the interproximal distance) of adjacent two teeth in the mouth of a patient is wide, a bit of foodstuff is forced in between the teeth, so that the interdentium tends to be forced open wedgewise. Repeated and continued occurrence of such states may be responsible for diseases such as peripheral gingivitis and even peripheral paradentitis.
For that reason, gauge plates having a variety of thicknesses have been used to permit a dentist to force open the interdentium by being shifted in a mesial-distal direction, when he or she makes judgement as to whether or not that proximal contact relation (esp., the interproximal distance) is proper.
Such gauge plates are called the dental contact gauge, which comprises generally a gauge plate formed of stainless steel or steel and a grip portion which is colored corresponding to the thickness of said plate and is formed of a synthetic resin. The critical interproximal distance which the dentist can force open the interdentum to be examined by shifting in a mesial-distal direction is expressed in terms of the thickness of that gauge plate. That interproximal distance is of the order of about 70 to 92 microns in the case of young men and women. Thus, three types of dental contact gauges currently available are generally 50 microns (green grip), 110 microns (yellow grip) and 150 microns (red grip) in thickness. In diagnosis, the gauge plates are inserted into the interdentium in order of thickness from thinner gauge plate to thicker ones till it cannot be inserted therein (50 .mu.m-110 .mu.m-150 .mu.m), and a dentist estimates a interproximal distance with reference to the following table.
TABLE ______________________________________ The criterion of diagnosis of a interproximal distance Interproximal Insertion of Gauge Plate Diagnosis distance ______________________________________ Green grip (50 .mu.m), Impossible Narrow Under 50 .mu.m Green grip (50 .mu.m), Possible and Proper 50.about.110 .mu.m Yellow grip (110 .mu.m), Impossible Yellow grip (110 .mu.m), Possible and Wide 110.about.150 .mu.m Red grip (150 .mu.m), Impossible Red grip (150 .mu.m), Possible Too wide over 150 .mu.m ______________________________________
Thus, the dental contact gauge comprising the combinations of three types of gauge plates of 50 microns, 110 microns and 150 microns in thickness or those having similar thicknesses is frequently used. Of these plates, the gauge plates of 50 microns and 110 microns in thickness are most frequently employed. Since the interdentium of adjacent two teeth is very complicated depending upon differences in the size and form of those teeth, the gauge plates of the dental contact gauge inserted into the interdentium receive a large force, and tend to deform. In particular, the gauge plate of 50 microns thickness is of high frequency in use, and is smaller in thickness than the other gauge plates, so that it tends to bend or yield, as shown in FIG. 3. For that reason, even when the used-up dental contact gauge is cleaned and sterilized by means of gas sterilization, boiling sterilization, high-pressure steam sterilization or dry-heat sterilization, the gauge plate is left deformed, as illustrated in FIG. 3, so that difficulty is involved in the insertion thereof into the interdentium during re-use. In addition, it makes it impossible to measure accurately the interproximal distance due to the deformation thereof. Furthermore, even after it has been treated by means of gas or heating sterilization, it gives a feeling of unsanitary to a patient.
To solve the problems resulting from the manipulation and appearance of the prior art gauge plate is possible by manually putting the deformed gauge plate to the original straight shape. However, this is very troublesome to a dentist. Although the 150-micron thick gauge plate of the dental contact gauge is of lower frequency in use, as compared with the other two types of gauge plate, difficulty is encountered in the repair thereof, once it has been deformed. Even if in the short run, all the three types of gauge plates should be replaced with new ones.